Caffeine

Caffeine is the most popular psychoactive drug consumed around the world.

On average about 70-80% of adults consume caffeine every day usually from coffee, tea, soda, or energy drinks. 

Coffee is the most popular beverage among all of them and its consumption is more worldwide after water. Approximately 1.6 billion cups are consumed daily.

The global consumption of caffeine has been estimated at 120000 tonnes per year.

Most People consume beverages containing caffeine to relieve or prevent drowsiness and to improve their cognitive performance.

Caffeine is a psychoactive drug that stimulates the central nervous system. It reversibly blocks the action of adenosine on its receptors and consequently prevents the onset of drowsiness induced by adenosine. 

Caffeine increases the release of acid in your stomach, it may interfere with the absorption of calcium in the body, and it increases your blood pressure. You may continue to feel the effects of caffeine for 4 to 6 hours. 

Caffeine also stimulates a certain portion of the autonomic nervous system.

Caffeine is a bitter, white crystalline purine, a methylxanthine alkaloid and it occurs naturally in various plants including coffee beans, tea leaves, cocoa pods, cola nuts, and guarana which are native to Africa, East Asia, and South America. 

Caffeine can be made by synthetic processes also and it is used in some medicines, foods, and drinks. Some pain relievers, cold medicines, and energy drinks are the best examples of synthetic caffeine.

Caffeine can have both positive and negative health effects. But, the effects depend upon the intake value of caffeine.  

The Food and Drug Administration recommends a maximum intake of 400mg in a day. 

Health Canada also advises a daily intake of no more than 400 mg for healthy adults.

In healthy children, moderate caffeine intake under 400 mg produces effects that are “modest and typically innocuous”. For children age 12 and under, Health Canada recommends a maximum daily caffeine intake of no more than 2.5 milligrams per kilogram of body weight. Based on the average body weights of children, this translates to the following age-based intake limits.

Age range

Maximum recommended daily caffeine intake

4–6

45 mg 

7–9

62.5 mg

10–12

85 mg (about ​12 cup of coffee)

The American Academy of Pediatrics recommends that caffeine consumption is not appropriate for children and adolescents and should be avoided.

Also, Health Canada has not developed certain advice for adolescents because of insufficient data.

Even so, Health Canada suggests that daily caffeine intake for adolescents be no more than 2.5 mg/kg body weight. This is due to the maximum adult caffeine dose that may not be suitable for lightweight adolescents or for younger adolescents who are still growing. 

According to Health Canada, the Women who are planning to become pregnant, pregnant women, and breastfeeding mothers need to limit their caffeine intake by 300 mg/day. 

Products containing caffeine are consumed and enjoyed by people around the world. 

So, the best way for consumers to avoid any adverse effects from caffeine is to become familiar with the many sources of this substance, to read product labels, and to moderate consumption of caffeine-containing products.

The following is provided to assist consumers in understanding the contribution of various foods to caffeine intakes.

Product

Serving Size

(unless otherwise

stated)

Milligrams of

Caffeine

(approximate values)

 

oz

ml

 

Coffee

 

 

 

Brewed

8

237(1cup)

135

Roasted and ground, percolated

8

237

118

Roasted and ground, filter drip

8

237

179

Roasted and ground, decaffeinated

8

237

3

Instant

8

237

76 – 106

Instant decaffeinated

8

237

5

 

Product

Serving Size

(unless otherwise

stated)

Milligrams of

Caffeine

(approximate values)

 

oz

ml

 

Tea

 

 

 

Average blend

8

237

43

Green

8

237

30

Instant

8

237

15

leaf or bag

8

237

50

Decaffeinated tea

8

237

0

 

Product

Serving Size

(unless otherwise

stated)

Milligrams of

Caffeine

(approximate values)

 

oz

ml

 

Cola Beverages

 

 

 

Cola beverage, regular

12

355(1 can)

36 – 46

Cola beverage, diet

12

355

39 – 50

 

Product

Serving Size

(unless otherwise

stated)

Milligrams of

Caffeine

(approximate values)

 

oz

ml

 

Cocoa Products

 

 

 

Chocolate milk

8

237

8

1 envelope hot-cocoa mix

8

237

5

Candy, milk chocolate

1

28g

7

Candy, sweet chocolate

1

28g

19

Baking chocolate, unsweetened

1

28g

25 – 58

Chocolate cake

2.8

80g

36

Chocolate brownies

1.5

42g

10

Chocolate mousse

3.2

90g

15

Chocolate pudding

5.1

145g

9

Values in table referenced from the following sources:

Harland, B.F. 2000. Caffeine and nutrition. Nutrition 16(7-8):522-526.

Shils, et al., 1999. Modern nutrition in health and disease. 9th Edition. Williams and Wilkins. Waverly Company, Baltimore

Benefits of Caffeine:

Consuming caffeine may be beneficial for several reasons but all of these are still not confirmed by research. 

Improve Alertness

An increased level of adenosine in the Basal forebrain induces sleep. 

Caffeine reversibly blocks the action of adenosine on its receptors and consequently prevents drowsiness and makes you more alert.